The commissioner shall require each group purchaser to submit data on revenue, expenses, and member months, as applicable. Revenue data must distinguish between premium revenue and revenue from other sources and must also include information on the amount of revenue in reserves and changes in reserves. Expenditure data must distinguish between costs incurred for patient care and administrative costs. Patient care and administrative costs must include only expenses incurred on behalf of health plan members and must not include the cost of providing health care services for nonmembers at facilities owned by the group purchaser or affiliate.